A message analyzer and a method for analyzing messages which are transmitted between the individual layers of the Open Systems Interconnection (OSI) reference model in the case of a communications system constructed according to the OSI reference model are described in the not prior published German Patent Application DE 102 04 657 Al.
This message analyzer thereby has means with which the causal relationship between individual messages from a chronologically listed sequence of all messages, irrespective of the respectively relevant layer of the OSI reference model, can be displayed. For this purpose, a supplementary item of information for each message which is transmitted is stored in each storage device during a test run, from which it can be determined by the analyzer, which messages were produced as a result of another message. Conversely, it is likewise possible to determine with respect to a specific message, which message is the cause of transmission of the specific subsequent message.
The selection of the message, for which preceding or subsequent messages which are in a causal relationship with the message are determined, is effected by means of selection of the message in a first region of a display device. In this first region of the display device, merely a limited number of messages can be displayed, the messages displayed respectively in the first region of the display device being displayed after reading in of the items of information from a storage device in table form. The arrangement of the items of information which are displayed in the first region is thereby effected on the basis of an item of time information which is stored for each individual message.
It is thereby disadvantageous that the number of messages displayed in the first region forms respectively only a small part of the entire number of messages which are stored in the storage device during a test run. In particular, a multiplicity of messages is displayed in the first region due to sorting of the messages on the basis of the item of time information, which messages can remain out with consideration during analysis of a test scenario since they are neither in a direct causal relationship with the remaining messages nor relate to the same layer of the OSI reference model.